Commutator-motor.



H. K. SCHRAGE.

COMMUTATOR MOTOR.

AEPLIUATION FILED SEPT. 9, 1911.

1,079,994. Patented Dec. 2, 1.913.

v cont-roller Ulli'llll) STATES HATENT QFFICE.

HIDDE KLAAS SCHRAGE, OIF VESTERS, SWEDEN, ASSIGNOR T0 ALLMNNA SVENSKA ELEKTBJSKA AKTIEBOLAGE T, or vEsTERs, SWEDEN.

COMMUTATOR-IVIOTOR.

Application led September 9, 1911.

To all whom t may concern.' I

Be it known that l, HIDDE KLAAs Sommer, acitizen of the Kingdom of the Netherlands, residing at Vester-s, Sweden, haveinvented new and useful Improvements in Commutator-Motors, of which the following is a specification. i

As is well known, it' is possible to regulate the speed of polyphase commutator metors by varying the voltage of the current supplied to the roter. To do this there is required either an induction controller or a transformer having a plurality of spaced leads or a controlling winding on the sta-tor having a iilurality of spaced leads and in the two lfst mentioned cases moreover a for accomplishing the regulation. llurtl'ier some kind of special device is required for obtaining a goed power factor, and in motors having a regulating winding on the. stator there has been used I for this purpose for instance a small mag- I iietizing transformer. lit-hout this trans l former the power factor would be Very unl favorable, due to the fact that the current of the secondary circuit. has the same frequency as that of the supply circuit.- 'All of the said auxiliary apparat-us render. the device very complicated and expensive.

The presentinvention relates to a commutator motor of the induction motor type, in which a regulation of the speed can be effected in a simple manner by brush displacing and which has a good power factor, no auxiliary devices being necessary to attain the latter result.

The invention is, chiefly, characterized in that each phase of a polyphase secondary Winding is for itself means of brushes through a variable portion of a closed continuous current Winding with commutator.

In the accompanying drawing I have in Figures 1-3 shoivnldiagrammatically three embodiments of my invention. Fig. 4 is an g end View and Fig. 5 a longitudinal section l of the commutator of the motors shown in Figs. l', 2 and 3i shortcircuited by Specification of Letters Patent.

Patented Dec. 2, 1913. Serial No. 648,453.

Referring to Fig.

phase winding on t-he rotor, which by means of slip rings and slidingr brushes can be con' vided with a. commutator- C (Figs. 4 and 5).

To said commutator belong' three pairs of brushes a,-b a,-b2 and cl3-3. The brushes al, (l2, o., are suit-ably provided on one common rocker ring A and the brushes 25 7) o, on a second rocker ring B, said rings being turnable in lependeiltly of each other.

S1, S2, S3 indicate the three phases of a three phase secondary winding disposed on the stator, each of said windings 'being connected to one of the brush pairs aar-21 aj`, and (z-b3 respectively and thereby shortcircuited through the portions of the regulating winding lyingr between the two brushes of each pair. The primary member of the motor thus comprises the winding P, while the seco'ndary member consists of the windings S1, S2 and S, which are connected in series with portions of the regulating winding. J

The motor now described works as fol` lows. Assumingthat three phase alternating current, is supplied to the primary Winding P from the generator G and that the commutator brushes of the regulating winding are so adjusted that the angle between the brushes (l1-77 olf-b2 and a3`b5 is null,

1, P indicates annee so that thus the stator windings' S1, S2,

I f the twov The field induces between the brushes l1- b1 (and similarly'for the brushes z2-'b2I and (lf-7b3) a voltage'of a frequency of and in the stator a voltage of the same. frequency. The voltage between a, and b1 1s:

e, const. X cwrgb,

where 9b is the strength of the field and fw. the number of turns of the portion of the regulating winding inclosed between -the brushes. The voltage in each stator phase 1s:

1 e, const. X cfwsqS where 9S indicates the same as before and ws is the number `of turns of each stator phase. The rotc-rtends to assume a speed at which the voltages e, and es are equal to eachother; consequently is:

The eld rotates at a speed :G of

and as above mentioned relative to the rotor at a .speed is possible toreguIate the speed of the motor to overor under-synchronous speed by varying w., z'. e. that portion of the regulating winding'l iingbetween the brushes.

should be o served that the voltages e,

t can nullify eachother only if the' secondary winding and the, portion of the regulat-ing winding incidentally used have the same axes so that said voltages are in phase with each other. It may, howeyer, be suitl able to displace the axes'of said windings in relation to each other, by displacing t e l brushes (1 1 b1, a2 b2 and a., b, somewhat in the samdirection whereby the voltages er and e; will-give a resultant by means of which the phase displacement of the motor tn .be compensated. The speeds kcalculated will hereby be influenced only to a small degree.

Fig. 2 shows a constructional 'form in which the regulating winding R and the main winding P of the rotor are connected to each other so that the main urrent ows also through the regulating winding. The arrangement and working are otherwise the saine as those described with reference to Fig. 1. I

The regulating winding and the commutator accordin to the present invention heed be dimensloned only for a part of the normal load of the motor depending on the limits of regulation. If it is desired to regulate the motor from 50% under-synchronous .to 50% over-synchronous speed, the, regulating winding and the commutator are dimensioned only for 50% of the load of the motor. The voltage'between the commutator segments may therefore be kept low without the brush surface becoming too large, on account whereof the commutation does not meet any .special difficulties.

The main winding of the motor may alsoO be carried out as a single phase-winding, so that the motor is supplied with single phase current while the secondary circuit is of three phase type. In such case a special starting phase must be arranged inthe ro- Y v usualy and a: an inductive resistance which are connected in series to each other between the supply wires 1, 2 and serve in well known manner ,to create a current which is Y .Y l y A ih the same manner as in the three phase It is evident rom this expression that 1t motor shown in Fig. 1.

During the starting operation the three statonphases may be shortcircuited directly through the brushes, a1 b1, a2' b2 and: a3 b3. After the starting the starting phase is disconnected by means of the circuit breaker a. If the single phase motor shown in Fig. 3 is regulated by turning the vo rocker rings .carrying the brushes in the same manner as in the three phase motor shown in Fig. 1, the field maintains its character as rotating ield of constant strength, and the speed. regulation takes place in accordance with the same law as in the three phase motor.

One may, if desired, arrange the primary winding and the regulating winding in the stator and, the secondar winding in the rotor. In such case it is, owever, necessary to arrange the brushes rotating, which renders the arrangement complicated.

Though I have'lshownA single and three phase motors in the'drawing it is obvious that my invention is not limited to any certain number of phases.

Having now described my invention what I claim as newand desire to secure by Letter Patent is:

1. In a dynamo electric machine, a rotor having a prlmarywinding, and a regulating winding, means for supplying current to said primary winding, a commutator connected to said regulating winding, brushes for said commutator and a stator carrying a polyphase winding each phase of which is connected independently of the other phases to a pair of said brushes bearing on said commutator, substantially as and for the purpose set forth.

2. In a dynamo electric machine, a rotor having a primary winding and a regulating winding connected to said primary winding and forming a part of the primary circuit, means for supplying current to said primary winding, va commutator connected to said regulating winding, brushes for said commutator, and a stator carrying a polyphase winding each phase of which is connected independently of the other phases to a pair of said brushes bearing on said commutator, substantially as and for the purpose set forth. c

3. A dynamo electric machine comprising a rotor having a primary winding andv a closed continuous current winding, slip rings connected to said primary winding,'a Commutator connected to said continuous current winding, adjustable brushes for said commutator, and a stator carrying a polyphase-winding each phase of which is connected independently of the other phases to a pair of said adjustable brushes bearing on said commutator, substantially as and for the purpose set forth.

4. A dynamo electric machine comprising a rotor having a primary winding and a closed continuous current winding, slip rings connected to said primar winding, a commutator connected to sai continuous current Winding, two rocker rings carrying a number of brushes bearing on said commutator, and a stator carr ing a polyphase winding, each phase of w ich is connected independently of the other phases to one brush on each of said -rocker rings, substantially as and for the purpose set forth.

5. In a dynamo electric machine, a rotor having a primary winding and a regulating winding, means for supplying current to said primary winding, a stator having a non-interlinked polyphase winding, and means for connectin each phase of said polyphase Winding w1th adjustable portions of said regulating winding.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HIDDE-KLAAS SCHRAGE.

Witnesses:

A. Roor, M. BAKER.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner ot Patents, Washingtoml). G. 

